The weak LA40 will work fine for the trainer. If you ever want to use your trainer engine in another plane down the road you might get something with a bit more power. On your 50th flight with your trainer when you're getting good, and you end up turning it into a pile of small wood pieces while flying inverted, it's nicer to pick a decent .46 out of the rubble and say "I really need to put this in an Ultra Stick anyways"... An LA40 isn't a good engine for many second planes. Then again, if you make your 50th flight and grease the landing and have a few extra $$$ you might donate the LA40 and trainer to your club, and get a new Ultra Stick 40 and Irvine .53 for your second plane. That doesn't happen very often though. Your first trainer is like your first bike, you love them till they die or get stolen.. - Joe